1. Field of the Invention
The present invention relates to the field of computing. More particularly, the present invention relates to a method for protecting encoded media content for network distribution.
2. Description of the Related Art
Recent technological advances involving digital data compression, network bandwidth improvement and mass storage have made networked distribution of media content more feasible. That is, media content, such as digitized music, can be conveniently distributed over the Internet. To protect the intellectual property rights associated with a particular piece of media content, it is desirable to obscure the media content to prevent pirating of the content.
Consequently, what is needed is a way for compressing media content for convenient network distribution, while also securing the compressed media content against unauthorized use.
The present invention provides a method for compressing media content for convenient public distribution, such as over a computer network, while also securing the media content for controlling distribution of the media content and for preventing unauthorized use of the media content. The advantages of the present invention are provided by a method of compressing media content in which a first predetermined portion of a media content is compressed using a first data-based compression algorithm and inserted into a first portion of a data frame. A second predetermined portion of the media content is compressed using a second data-based compression algorithm and is inserted into a second portion of the data frame. The second predetermined portion of the media content is different from the first predetermined portion of the media content, and the second data-based compression algorithm is different from the first data-based compression algorithm. Preferably, at least one of the first and second data-based compression algorithms is a private data-based compression algorithm. The first and second portions of the data frame are separated by a predetermined header code, or can be separated by relative positions of the first and second predetermined portions of compressed media content within the data frame.
The present invention also provides a method for inserting a data stream not associated with the media content into a compressed media content bit stream. The inserted data stream is carried by at least one symbol in at least one initial data set associated with the DBCA. A preferential implementation uses designated symbols in one or more Huffman codebooks for embedding a watermark in the compressed bit stream. The value of the watermark bits recovered from the bit stream depend upon either the values associated with the symbols or alternatively the position of the symbol in the compressed bit stream.
According to the invention, a plurality of data frames are generated and are made available for distribution, for example, by transmission over a computer network, such as the Internet. Alternatively, the data frames can be made publicly available for storage in a memory device, such as a CD ROM.
A plurality of predetermined portions of the media content can be compressed using data-based compression algorithms and grouped into a respectively different portion of the data frame. Each respective predetermined portion of the media content is different from the first and the second predetermined portions of the media content. Similarly, the data-based compression algorithm used to compress a respective portion of the media content is different from the first and the second data-based compression algorithms. Preferably, at least one of the data-based compression algorithms is a private data-based compression algorithm.
Initial data associated with each private data-based compression algorithm is encrypted and made publicly available when the data frames are made available. The encrypted initial data is grouped into a data envelope within a data frame that is preferably available no later than a first data frame containing media content compressed using the private data-based compression algorithm with which the encrypted initial data is associated, but can be made available during a later data frame. Examples of initial data associated with at least one private data-based compression algorithm include a Huffman code-book and/or a vector quantization code-book.
Further, the present invention provides a method of compressing media content in which a first predetermined portion of a media content is compressed using a first data-based compression algorithm, a second predetermined portion of the media content is compressed using a second data-based compression algorithm, and a third predetermined portion of the media content is compressed using a third data-based compression algorithm. The second predetermined portion of the media content is different from the first predetermined portion of the media content and the second data-based compression algorithm is different from the first data-based compression algorithm. The third predetermined portion of the media content is different from the first and the second predetermined portions of the media content, and the third data-based compression algorithm is different from the first and the second data-based compression algorithms. The first, second, and third compressed predetermined portions of the media content can be grouped into first, second, and third portions of a data frame, respectively. This data frame may be received and each portion may be decompressed.
According to the invention, the media content can include audio content, such as music and/or speech, images, video content, graphics and/or textual content.